JPH0753768B2 - Allyl-terminated polyisobutylene polymer and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Over the last two decades, various organosilicon compounds have been shown to react with various electrophilic reagents. The reaction is carried out by removing organosilicon compounds having multiple bonds of 1, 2, or 3 atoms removed from silicon, that is, arylsilane, vinylsilane, alkynylsilane, silyl enol ether,
Formed with allylsilane, benzylsilane, homoallylsilane and alkylsilanes under violent conditions. Most of these reactions are expected to proceed by new electron attack on silicon leading to intermediate cation beta. Such reactions are highly regioselective due to cation stabilization. Silyl groups are generally lost during subsequent steps, resulting in electrophiles and compounds with multiple bonds at predictable positions.

Electrophilic substitution of organosilicon compounds is at least one of the pursued synthetic methods in polymer synthesis. Due to the relatively weakly polarized Si-C bonds, organosilanes behave as weakly reactive organometallic compounds. Therefore, they can be handled more conveniently than other organometallics, ie they generally do not require an anhydrous or inert atmosphere and are inert in the presence of various functional groups. There are few studies on electrophilic substitution between a carbon cation or a substance having a relatively high positive charge on a carbon atom and an organosilicon compound. Adamantyl and tert-butyl halides have been shown to displace selected unsaturated organosilicon compounds in the presence of Lewis acids (eg, I. Fleming et al. Synthesis,
1979, 446; T. Sasaki et al., J. Org Chem., 1980 (45), 35.
See 59).

Problems to be Solved by the Invention Since polyisobutylene is difficult to crosslink, its use is limited. Copolymerization with small amounts of isoprene was found to give unsaturated residual sites, and thus sulfur vulcanization, and led to the commercialization of butyl rubber during World War II. In addition to being chemically and ozone inert, butyl rubber has an extremely low permeability to gases and is therefore widely used in tire tubes. Low molecular weight polyisobutylene oils have recently been used to increase the viscosity of lubricating oils and high molecular weight non-vulcanized polymers are used in adhesives, cokes, sealants, and polymer additives.

The co-weight of polyisobutylene and polydialkylsiloxane, so-called silicone, produces the desired material. Surprisingly, there are very few studies on soft block-soft block copolymers of polydimethylsiloxane (PDMS) with polyisobutylene or other organic polymers. Such copolymers are expected to be fluid materials. Comb type PDMS polybutadiene soft block-soft block copolymers are known but do not have the ozone resistance and yellowing resistance of PIB silicone block copolymers.

A simple method to bond a polydimethylsiloxane polymer to an organic polymer to form a block polymer is optimally a terminal olefin, H ₂ C = CHR with a platinum catalyst added to the SiH moiety to form a S
Hydrosilylation to produce iCH ₂ CH ₂ R
n) Method by reaction.

Industrially, isobutylene is polymerized with aluminum chloride at low reaction temperatures such as -100 ° C. The product has predominantly saturated aliphatic end groups.

Polyisobutylene (PIB) having unsaturated positions can be produced by copolymerization of isobutylene with a small amount of isoprene. The resulting unsaturation causes vulcanization, but the hydrosilylation is suppressed or prevented because the unsaturation site is predominantly internal. The terminal olefin terminal group at one end is BCl ₃ and CH ₂ ═CHC (C
It obtained Te cowpea to initiate the polymerization of the H _{3) 2} Cl.
The other end of the polymer is terminated with chloride. CH ₂ = CHC (CH ₃ )
_{Although the 2} -group is terminal, it is not very reactive in hydrosilylation due to the steric hindrance provided by the two methyl groups. Moreover, only (AB) block copolymers are formed (where A represents a silicone block and B represents a hydrocarbon block). Another method is to use a special dichlorocarbon co-initiator such as dicumyl parachloride with BCl ₃ or use chlorine as the co-initiator to make polymers with chlorine at each end. Is the way. The chlorine-terminated polymer is then refluxed with potassium tert-butoxide for 20 hours, cooled and
Turn washed with water, due to due to drying connexion with de-hydrohalogenation generating a _{-CH 2 -C (CH 3) =} CH 2 group (Kennedy
See U.S. Pat. No. 4,342,849 issued Aug. 3, 1982). This terminally unsaturated PIB gradually undergoes hydrosilylation. Hydrosilylation is slow because the end groups are sterically hindered. Therefore, it undergoes rapid hydrosilylation at both ends (A
B) _X block copolymer (where x is to produce a CH ₂ = CHCH ₂ polymers such as -PIB-CH ₂ CH = CH ₂ to generate two or more), non-failure allyl PIB, CH ₂ = CHCH ₂ -, quick to provide terminal functionality, there is a need to provide a simple and low cost method. Such materials have many applications, such as electronic potting gels, surfactants that make PIB compatible with silicones, pressure sensitive adhesives and non-sticking chewing agents.
It is useful as a gum.

Means for Solving the Problems The present invention provides a tertiary chloro-capped
It relates to a method for preparing allyl-terminated polyisobutylene by allylation of polyisobutylene (PIB) with allyltrimethylsilane. Its synthesis is the first example of the use of silyl cinson allyltrimethylsilane in polymerization chemistry. Synthesis begins by BCl ₃ catalyzed mono- or oligo-tertiary chloride "Inifua (inifer)" initiated polymerization of isobutylene, followed the addition of hexane, allyltrimethylsilane and TiCl ₄ in the same reaction vessel. This method produces an allyl-terminated PIB.

The present invention relates to a process for the synthesis of novel end-functional polymers such as polyisobutylene having terminal unsaturation such as allyl groups. In practicing the method of the present invention, chlorine-functional or mixed chlorine / olephine-functional telechelic-functional isobutylenes, which initially involve the polymerization of monomers, and a multiplicity of simultaneous initiating polymerizations and acting as transfer agents. It is necessary to start with a functional compound. For this compound,
We use the term “Inifur”, which is a disclosure agent (in
itiator) and transfer.
Inifers are generally mono- or oligo-tertiary organic chlorides such as (ClC (CH ₃ ) ₂ C) _X C ₆ H _(6-X) (where x =
1, 2 or 3) or the inifer is H ₂ C = CH
It is a chloro olefin such as (CH ₃ ) ₂ CCl.

Therefore, the object of the present invention is to provide a new telecheli.
It is to provide an allyl-terminated polyisobutylene polymer. Another object of the present invention is to provide a method for the synthesis of polyisobutylene having an allyl unsaturated terminal position.

The present invention relates to a process for preparing an allyl-terminated PIB by allylation of a third chloro-terminated capped PIB with allyltrimethylsilane by electrophilic substitution in a one-reactor, two-step process. In the present invention, "the third chloro-terminal capped PI
"B" or "tertiary chlorinated polyisobutylene" means a polyisobutylene molecule having at least one tertiary carbon atom to which a chlorine atom is attached. Furthermore, the present invention provides PI
A method in which the prepolymer of B is prepared from isobutylene (IB) by the inifer method in the presence of BCl ₃ and inifer. The reaction mixture obtained by polymerizing IB into PIB was not quenched, but allyltrimethylsilane and Friedel-Crafts Lewis acid catalyst, preferably TiCl ₄
The mixture with and is added in excess. The 3-fold (molar) excess of BCl ₃ remaining in the polymerization of IB with respect to the tertiary chloro end group is Et ₂ A.
It completely destroys the allylation activity of lCl and significantly reduces the allylation activity of SnCl ₄ . In contrast, the allylation efficiency of TiCl ₄ is not adversely affected by the presence of BCl _{3 according to} the invention. Low molecular weight (Mn = 1,000 to 4,000) PIBs prepared with BCl ₃ and dicumyl chloride Inifer undergo 10 to 30 mono-reactive ends undergoing intramolecular cycloalkylation to give indanyl end groups in the presence of Lewis acids. % May be included. However, in accordance with the present invention, the absence of full-end alkylation and formation of indanyl end groups results in a stoichiometric molar excess of allyltrimethylsilane and TiCl 3 to tertiary chloro-terminated capped groups. _{Using 4} has been achieved. Allyl-terminated PIB polymers can be isolated by this method.

The use of other metal halides and metal complexes is within the scope of this invention. Other Friedel-Crafts Lewis acid metal catalysts that work in the present invention include, but are not limited to, zirconium halides, vanadium halides, iron halides and complexes, aluminum halides and aluminum alkyl halides.

Further, the present invention relates to a process for preparing an allyl-terminated polyisobutylene polymer, which process includes but is not limited to boron trichloride and titanium tetrachloride, tin tetrachloride, or in the absence of boron trichloride, but not limited to diethyl aluminum chloride. Forming an allyl-terminated polyisobutylene polymer by reacting a trichlorinated isobutylene with allyltrimethylsilane in the presence of Alkyl aluminum chloride having an alkyl group having 1 to 6 carbon atoms also works in the present invention. Formula ▲ R ² ₃ ▼ SiCH ₂ CR ³ CH ₂ (R ² and R ^{3 in the} formula
Is selected from the group consisting of groups consisting of hydrogen and alkyl groups containing 1 to 6 carbon atoms), and the allylation of polyisobutylene with substituted allylsilanes is within the scope of the present invention.

The present invention further relates to a process for preparing an allyl-terminated polyisobutylene polymer, which process comprises: (A) polymerizing isobutylene in a mixture of methyl chloride and hexane in the presence of boron trichloride and inifer. Is of the formula AYn [wherein A is selected from the group consisting of fused and unfused aromatic compounds having 1 to 4 rings, and linear and branched aliphatic compounds having 3 to 20 carbon atoms, Y is The following formula Embedded image wherein R and R ¹ are each selected from the group consisting of alkyl and aryl, X is a halogen selected from the group consisting of chlorine and bromine, and n is 1
Is an integer of 6]; (B) increasing the hexane concentration of the resulting reaction mixture to improve the solubility of the polymer; (C) adding allyl-functional silane and tetrachloride to the reaction mixture. Allylating the polyisobutylene by adding titanium chloride, wherein the allyl functional silane is of the formula ▲ R ² ₃ ▼
SiCH ₂ CR ³ CH ₂ (wherein R ² and R ³ are hydrogen and 1 to
Selected from the group consisting of alkyl groups having 6 carbon atoms]
(D) a step of advancing and completing the allylation reaction; (E) a step of injecting the reaction mixture into a basic aqueous solution; and (F) an allyl-terminated polyisobutylene polymer. Is isolated and purified.

The term "completed" of allylation here means that the allylation reaction is continued until the main part of polyisobutylene is allylated.

It was found that the efficiency of Friedel-Crafts Lewis acid for the allylation of 2,4,4-trimethyl-2-chloropentane (TMP-Cl) decreases in the following order: (CH ₃ CH ₂ ) ₂ AlCl> The difference in catalytic activity of TiCl ₄ > SnCl ₄ >> BCl ₃ Friedel-Crafts type Lewis acids increased as the reaction temperature increased. The yield was increased by lowering the temperature from 20 ° C to -70 ° C. Allylation at -70 ° C. uses a 2-fold excess (mole) of allyltrimethylsilane over the third chloro-terminated capped group in the presence of (CH ₃ CH ₂ ) ₂ AlCl, TiCl ₄ or SnCl _4. Therefore, it was quantitative. The degree of ionization by Friedel-Crafts type Lewis acid seems to control the substitution yield. Ti
It has been found according to the present invention that Cl ₄ is the most efficient allylation catalyst for trichlorinated polyisobutylene in the presence of BCl ₃ . Although diethylaluminum chloride was a little more efficient than TiCl _{4 in} the absence of BCl ₃ ,
It was inactive in the presence of BCl ₃ .

A dramatic solvent effect in the electrophilic catalysis of allyltrimethylsilane with TMP-Cl was also observed. The polarity of the medium is CH
₂ Cl _2, CH ₂ Cl ₂ and mixtures and HenTsuta Te cowpea to use pure hexane hexane. Model compound TM in pure hexane
In the case of P-Cl, the allylation is significantly suppressed,
In the presence of about 30% CH ₂ Cl ₂ , 70% hexane or pure CH ₂ Cl ₂ , the efficiency of allylation is extremely high. Accordingly, a preferred embodiment of the present invention is the allylation of a "one reaction vessel two step" PIB, wherein the reaction medium mixture of about 80% methyl / 20% hexane used to polymerize IB to PIB is: Addition of hexane converts to about 45:55 CH ₃ Cl: hexane.
Another preferred embodiment of the present invention is a "two-reactor two-step" allylation of PIB, which comprises a second mixture of 80% methyl chloride / 20% hexane used to polymerize IB into PIB.
The solvent composition of 45:55 CH ₂ Cl ₂ : hexane is substituted in the process. Therefore, the concentration of hexane can be increased to a concentration within the range of 55 to 70% by weight.

Diethyl aluminum chloride ((CH ₃ CH ₂ ) ₂ AlCl) is Eth
yl (Baton Rouge, Louisiana, USA). Boron trichloride (BCl ₃ ) was obtained from Union Carbide Corporation (Danbury, CT, USA). Titanium chloride (TiCl
₄ ) was obtained from Aldrich Corporation (Milwaukee, Wisconsin, USA). Tin chloride (SnCl ₄₎ is Fuitsushiya over, Inc. (the United States, Pennsylvania, Piitsubagu) was obtained from. Allyltrimethylsilane is the Petrarch System
(Bristol, Pennsylvania, USA). Chloro PIB was prepared by the semi-continuous inifer method of J. Kennedy et al. (J. Polym. Sci. Polm. Chem. Ed., 18 , 1523, 1980).

Examples Example 1: "1 reaction vessel 2-step process" Allylation of chloro PIB In a culture tube, 0.000281 mol of para-dicumyl chloride, 0.00154 mol of BCl ₃ of 80 parts of methyl chloride and hexane 20 were added.
Isobutylene was polymerized for 60 minutes at -80 ° C by passing 0.0224 mol of isobutylene through 25 ml of a solution of part. After 1 hour, the solvent composition was adjusted to 4 by adding hexane.
Changed to 5:55 CH ₃ Cl: Hexane. Without quenching the reaction, there was about a 2-fold molar excess of allyltrimethylsilane (0.00109 mol) and T with respect to the tertiary chloro group of cumyl chloride.
iCl ₄ (0.000702 mol) was added simultaneously at −80 ° C. After 60 minutes, the system was poured at 0 ° C. into a solution of saturated NaHCO ₃ . The allylated polymer was precipitated with acetone, isolated by filtration, dried and dissolved in CCl ₄ . Proton NMR
The spectrum confirmed the formation of 98% bis-allyl-PIB. GPC showed a number average molecular weight of 3,700.

Example 2: Allylation of isolated and purified chloro PIB Chloro PIB is a semi-continuous inifer method of Kennedy et al. (J. Pol.S.
ci., Polm. Chem. Ed., 18 , 1523, 1980).
About 0.5 g of the third chloro-terminated PIB was dissolved in 5 ml of dichloromethane and placed in a 50 ml glass reactor equipped with a Teflon stopcock. A 3-5 molar excess of allyltrimethylsilane with respect to the tertiary chloro end groups was added with a syringe under a nitrogen atmosphere. The reaction is carried out under a nitrogen atmosphere in a molar excess of 2-3 times.
It was started by adding TiCl ₄ Lewis acid with a syringe. The homogeneous charge was occasionally stirred and poured into saturated NaHCO ₃ solution (25 ml) after 25-75 min. The organic phase was separated, dried over anhydrous MgSO _4, volatiles were evaporated in vacuo. Dissolve the residual polymom in a small amount of hexane (about 2 ml), precipitate with acetone, separate, wash with acetone,
The volatiles were then removed by evaporation in vacuum overnight. Dissolve the dried polymer in CCl ₄ (20-30%),
Proton NMR analysis confirmed the formation of allyl PIB.

Example 3: Allylation in situ of chloro PIB Polymerization of isobutylene was 0.063 mol / dm in culture tubes.
³ chloride cumyl, from 0.065 to 0.180 mol / dm ³ of allyltrimethylsilane and 1.2 mol / dm ³ of quickly due connexion KoTsuta to the addition of BCl ₃ 0.80 ml to stirred solution 22ml of isobutylene. The reaction was terminated by the addition of a few ml of prequenched methanol and the precipitated allyl-terminated PIB polymer was isolated.

Example 4: In TiCl ₄ catalyst allylation culture tubes "second reaction vessel 2 Scheme" Chloro PIB 0.000562 mol para chloride dicumyl 0.
00308 mol of BCl ₃ in 80 ml of methyl chloride and 20 parts of hexane in 25 ml of isobutylene (0.0224 mol) at −80 ° C.
Isobutylene was polymerized by passing through for 60 minutes. 1
After time, to terminate the reaction, the chloro -PIB isolated and washed to remove residual BCl _3. Next, 4 g of chloro-PIB is added.
It was taken up in 10 ml of a solvent composition of 5/55 CH ₂ Cl ₂ / hexane. A 4-fold molar excess of allyltrimethylsilane (0.00422 mol) and TiCl ₄ (0.00236 mol) was added simultaneously at −80 ° C. with respect to the tertiary chloro groups of cumyl chloride. After 60 minutes, bring the system to 0 ° C.
Was poured into a solution of saturated NaHCO ₃ (50 ml). The allylated polymer was precipitated with acetone, isolated by filtration, dried and dissolved in CCl ₄ . The proton NMR spectrum is
Generation of allyl-PIB was confirmed.

Example 5: "2-reactor 2-step" dimethyl-aluminum chloride-catalyzed allylation of chloro PIB In a culture tube, 0.0562 para-dicumyl chloride, 0.0030
25 parts of a solution of 8 mol of BCI ₃ in 80 parts of methyl chloride and 20 parts of hexane
Isobutylene was polymerized by passing isobutylene (0.0224 moles) through 180 at 180 for 1 hour. One hour later,
The reaction was terminated, the chloro -PIB isolated, to remove any residual BCl ₃ and washed. Next, 1.0 g of chloro-PIB was taken in 10 ml of a solvent of 45/55 CH ₃ Cl / hexane. A 3-fold molar excess of allyltrimethylsilane (0.00314 mol) and dimethylaluminum chloride (0.00218 mol) were added simultaneously at −80 ° C. with respect to the tertiary chloro groups of cumyl chloride. After 60 minutes, the system was poured into 50 ml of a saturated NaHCO ₃ solution at 0 ° C.
The allylated polymer was precipitated with acetone, isolated by filtration, dried and dissolved in CCl ₄ . Proton NMR spectra confirmed the formation of bis-allyl-PIB.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Antonio Popp Wright 7300 Rodson Jief Aason Road, Michigan, USA

Claims (4)

[Claims] 1. An allyl-terminated polyisobutylene polymer comprising forming an allyl-terminated polyisobutylene polymer by reacting a trichlorinated polyisobutylene with allyltrimethylsilane in the presence of a Friedel-Crafts type Lewis acid. How to make a coalesce. 2. In the presence of titanium tetrachloride and boron trichloride,
A method of making an allyl-terminated polyisobutylene polymer comprising reacting a chlorinated poisobutylene with allyltrimethylsilane to produce an allyl-terminated polyisobutylene polymer. 3. In the presence of a metal halide selected from the group consisting of titanium tetrachloride, aluminum chloride, zirconium chloride, iron chloride, vanadium chloride, tin tetrachloride and alkylaluminum chloride having an alkyl group of 1 to 6 carbon atoms. Wherein the quaternary chlorinated polyisobutylene is reacted with allyltrimethylsilane to produce an allyl terminated polyisobutylene polymer. 4. (A) Boron trichloride and inifer [wherein the inifer is selected from compounds having the formula AYn, where A in the formula
Is selected from the group consisting of fused and non-fused aromatic compounds having 1 to 4 rings and linear and branched aliphatic compounds having 3 to 20 carbon atoms, and Y is (Wherein R and R ¹ are each selected from the group consisting of alkyl and aryl, X is a halogen selected from the group consisting of chlorine and bromine), and n is an integer from 1 to 6. In a mixture of methyl chloride and hexane in the presence of [a], (B) increasing the hexane concentration of the reaction mixture; (C) adding an allyl-functional silane to the reaction mixture. The allyl-functional silane is represented by the formula ▲ R _{2 3} ▼ SiCH ₂ CR ³ CH ₂ (wherein R ²
And R ³ are each selected from the group consisting of hydrogen and an alkyl group having 1 to 6 carbon atoms) and a step of allylating polyisobutylene by adding titanium tetrachloride; D) advancing and completing the allylation reaction; (E) injecting the obtained reaction mixture into a basic aqueous solution; and (F) isolating and purifying an allyl-terminated polyisobutylene polymer, A process for producing an allyl-terminated polyisobutylene polymer comprising